CSS changes

here's a sidebar and some CSS work.  

on the sidebar side: 
- removed font-awesome and add octicons (the book looked nicer in another glyph set -- http://glyphsearch.com/ is veryhelpful)
- chapters are inserted via python
- some formatting is funky, like background-color of current chapter because of text indent, I'm still look at this....
  
I'm not sure about how to style things on the sidebar, but I've made some CSS choices for the main text to make it more readable (IMO): 
- reasonable tabs for code
- using a more code like monospace font
- sidebar on codeblocks
- code wrap 
- formatting on lists in the articles
- removed some horizontal rules
- removed some extraneous spacing
- changed overall width to 650 -- I found the 800 width harder to read and I'm trying to match some good online books like the pro-git, etc
- alot of images were having trouble with the width thing that was making them full width (for example: http://imgur.com/pMq1knZ) so I've made them resize to width if they are larger, but not go full width if not but just be centered.  To make the caption drop, I've added a div to clear (this is in python)

there's still alot of CSS stuff to be done, and I'm sorry this is not a more broken out commit, I was just messing around trying to make it more readable. 

a couple of snaps 

![screen shot 2014-09-10 at 6 35 36 am](https://cloud.githubusercontent.com/assets/142897/4216172/57a02d2c-38d6-11e4-8048-acf81569dae5.png)

![screen shot 2014-09-10 at 6 35 48 am](https://cloud.githubusercontent.com/assets/142897/4216177/5bda6416-38d6-11e4-8cc2-939ed74c5a7d.png)

sidebars need some styling thought / work 

![screen shot 2014-09-10 at 6 36 03 am](https://cloud.githubusercontent.com/assets/142897/4216182/6408763c-38d6-11e4-87eb-1414f36f0788.png)

![screen shot 2014-09-10 at 6 36 14 am](https://cloud.githubusercontent.com/assets/142897/4216183/640bd99e-38d6-11e4-9c2b-3f1bebac6750.png)